DIY Request - Make the Rear Performance Bumper PDC Compatible

[Maconer98]

Hello all-
So my rear bumper was hit and damaged but I was able to find and purchase a used bumper off someone that is in great shape. Only problem is that I have the PDC option and the "new" bumper I purchased doesn't have the PDC holes cut out. I bought it anyway because the price was too good to say no and I figured I'd be able to make them on my own. Has anyone done this in the past with any PDC on any car (do a PDC retrofit)? Obviously if you've done it on a 135i that would be extremely helpful but if not, I'd like to know what the process was like and what tools you used.

Thanks.